Cable equalizer



April 16, 1935. J. DUNLOP CABLE EQUALI ZER Filed Jan. 14, 1933 2Sheets-Sheet 1 INVENTOR Patented Apr. 16, 1935 UNITED STATES PATENTOFFICE CABLE EQUALIZER Application January 14, 1933, Serial No. 651,685

9 Claims.

My invention relates to cable equalizers and more particularly toequalizers for the hoisting cables employed in operating elevator carsin their hatchways.

In elevators in which the car is suspended by a plurality of hoistingcables or ropes, considerable difficulty has been experienced inmaintaining the cables in such condition that each one carries an equalproportion of the load provided by the car and its counterweight. causesof this difliculty are the tendency of the cables to stretch unequallyunder load, the differential in diameter of the cable grooves in thehoisting drum arising from mechanical imperfections or wear, anddifferences in the diameters of the cables themselves. Although:elevator cables are very carefully constructed at present, it is stillimpossible to so make them that they will not stretch in service or havesome slight difference in diameter. Furthermore, as the use of thecables continues, their diameter may change by reason of wear. Thegrooves in the cable drum are usually almost perfectly constructed, butthey also tend to wear unevenly in long continued service.

One of the objects of my invention is to provide an equalizer for soconnecting the hoisting cables to the car and its counterweight thateach cable will carry an equal share of the total load and toautomatically maintain such equal distribution of the load, even thoughthe cables change in length by reason of stretching, or the diametersof, the cables or the cable grooves change by reason oi wear.

Another object is to provide an equalizing means that willeffect an evendistribution of the load on the cables under all conditions withoutmoving the cables out of their axial alignment.

A further object is to provide an equalizer of high mechanicaleiiiciency in which the cable drawbars shall have comparatively shortstrokes, and in which the drop of the car to the stops provided on theequalizer, in the event of a cable breaking, shall be as short aspossible.

A still further object is to provide an equalizer which will permit suchan arrangement of the hoisting cables that they become, in effect, ap- 0proximately one continuous cable laced from the car and over thehoisting drum to the counterweight.

It 'is also an object ,ofmy invention to provide an equalizer that issimple and inexpensive to manufacture and maintain in operation, and

The usual which shall not catch and hold dirt or grit in its workingparts.

Other objects will, in part, be obvious, and will, in part, appearhereinafter in the following description, taken in conjunction with theaccompanying drawings, in which:

Figure 1 is a view in perspective of an elevator provided withequalizers constructed in accordance with my invention;

Fig. 2 is a diagrammatic representation of the cables and equalizerslaid out in a plane;

. Fig. 3 is a view representing a vertical section of one side of one ofthe equalizing units embodied in Fig. l; i

Fig. 4 is a sectionalview taken on the line IV-IV of Fig. '3;

Fig. 5 is a top plan view of the equalizing unit shown in Fig. 3, withthe top mounting plate removed to permit a view of the interior of thedevice; and

Fig. 6 is a diagrammatic representation of the system of roping thehoisting cables employed for the elevator illustrated in Fig. 1.

Referring more particularly to Fig. 1, I have illustrated an elevatorcar C as suspended by a plurality of hoisting cables Ca that pass over ahoisting drum D to a counterweight Cw, the drum being provided withsuitable grooves G for the cables. The car may be called a service loadand the counterweight a counter-balancing load.

The car C comprises a cab l disposed in a sling comprising a pair ofupright members 2 and 3 that are connected at their upper ends bya pairof channel members 4. The hoisting cables Ca are connected to the car Cthrough a plurality of 35 drawbars or thimble rods 5 (see Fig. 2) thecables being attached to the upper ends of the drawbars in the usualmanner-- s In order that the load of the car upon the cables may beevenly distributed among the cables, the lower ends of the drawbars 5are connected to the car by means of my improved equalizing meanscomprising a plurality of equalizing units I mounted on the underside ofan adjusting plate 8, which, in turn, is secured to the underside of a45 mounting plate 9 attached to the underside of the channel members 4.r

The counterweight Cw comprises aplurality of weights I!) mounted in acounterweight sling H constructed in the usual manner. The cables Ca areconnected to the counterweight through a plurality of drawbars l2 thatare similar to the drawbars 5 connecting the cables to the car.

In order that the load of the counterweight Cw may be equallydistributed among the hoisting cables, and also in order that thehoisting cables may automatically adjust themselves to any change intheir lengths and to differences in their diameter and differences inthe diameters of the hoisting drum grooves, the lower ends of thedrawbars |2 are connected to the counterweight sling II by an equalizingmeans I4. The equaliz ing means l4 comprises a pair of equalizing unitsl5 attached to the underside of an adjusting plate l5 mounted on theunderside of the top portion of the counterweight sling.

Referring now to Figs. 3, 4 and 5, each of the equalizing units 1attached to the car comprise a hollow rectangular housing 20, in which apair of equalizing bars 2| and 22 are disposed to slide upwardly anddownwardly. The cooperating sides of the housing and the bars areconstructed in planes parallel to the longitudinal axes of the bars forthe purpose of preventing lateral movement of the bars while permittingtheir longitudinal movement. The adjacent inner faces 24 and 25 of thebars are beveled upwardly for cooperative engagement with an equalizingroller or equalizing member 26 so disposed as to prevent simultaneousupward movement of the bars.

The equalizingroller 26 is rotatably and movably suspended in itsposition between the adjacent beveled faces of the bars by a shaft 21the ends of which are supported in a pair of side straps 2B and 29 whichswing from a large shaft 30 set in the side walls of the housing. Awheel 3| is rotatably mounted between the upper ends of the straps 28and 29 on the shaft 80. The size and position of the wheel 30 are suchthat its periphery may be engaged by the periphery of the roller 26 andthereby provides an antifriction track upon which the roller may rotateand revolve in accordance with the forces exerted upon it by the beveledfaces of the equalizing bars.

In order that the bars 2| and 22 may move easily, a plurality ofanti-friction elements comprising a plurality of bearing rollers 33 aredisposed between the rear sides of the bars and the cooperating Walls ofthe housing. The bearing rollers 33 for the bar 2| are mounted in aroller cage 34 by means of a plurality of pins 35. A small projection 36at the top of the roller cage extends over the top of the bar 2| toprevent the cage and rollers from dropping downwardly when the apparatusis in use. A depression 31 is provided in the upper part of the bar 2|to receive the projection 36 when the bar 2| moves upwardly where itengages the top plate 3. The roller cage for the bar 22 is similar tothat just described for the bar 2|.

As shown, the bars 2| and 22 are provided with holes 38, through whichthe drawbars 5a. and 5b may be inserted and locked by a plurality ofnuts 38 for the purpose of connecting the cables to the bars.

In assembling the equalizing units for use in an elevator, it has beenfound advisable to firmly secure them to the underside of the supportingplate 8, as by means of a welded joint shown at 40 in Fig, 3. The plate8 is provided with holes 4| through which the upper ends of the drawbars5 pass and it also acts as a means for limiting the upward movement ofthe equalizing bars. For instance if the cable attached to one of thebars breaks, the consequent upward movement of the other bar is limitedto a predetermined distance such as three inches. 7

In order to retain the parts of the equalizing units in their assembledposition while they are being shipped and handled, a pair of bolts 43and 44 are disposed in the lower tips of the housing 20 in position toextend through the lower portions of the roller cages and into holes 45and 46 in the bars 2| and 22. The bolts 43 and 44 will hold the parts intheir assembled position until they are installed in the elevator andplaced in use, but the bolts must be removed before the equalizers areactually placed in operation.

The equalizing units Is for the counterweight are similar to the unitsfor the car and are mounted in the same manner upon the plate l6.

Although the usual system of roping may be employed in connecting thecar and the counterweight by the hoisting cables, I prefer to employ thenovel roping arrangement shown diagrammatically in Fig. 6.

In this arrangement, the counterweight ends of the outer cables 50 andare dead-end connected to the counterweight; the car ends of the cables50 and 5| are individually connected to the cooperating bars 2| and 22of the equalizing unit la; the counterweight ends of the intermediatecables 5| and 52 are individually connected to the cooperating bars 2|and 22 of the equalizing unit |5a; the car ends of the intermediatecables 52 and 53 are individually connected to the cooperating bars 2|and 22 of the equalizing unit 1b; the counterweight ends of theintermediate cables 53 and 54 are individually connected to thecooperating bars 2| and 22 of the equalizing unit I52); and the car endsof the cables 54 and 55 are individually connected to the cooperatingbars 2| and 22 of the equalizing unit To.

By connecting the cables through the equalizing units as described, Isecure practically a continuous cable that is laced over the hoistingdrum from the counterweight to the car, thereby permitting aparticularly accurate automatic adjustment of the load in such mannerthat an equal proportion of it is borne by each cable.

For instance, if the cable attached to the drawbar 5a in the movable bar2| stretches, or the groove in which it operates becomes deeply worn,the difference in the force exerted upon the roller 26 by the bars 2|and 22 will force that roller to the left (see Fig. 3), whereupon thebar 22 will move upwardly and the bar 2| will move downwardly until theforce exerted by them on the roller 28 is equalized and the bars come toa stop, in which position the tension or pull upon the cables attachedthereto will be equal.

Inasmuch as the bars 2| and 22 move vertically on the roller bearingsand have a rolling engagement with the roller 26 and the controller inturn has a rolling engagement with the wheel 3|, it will be seen thatvery little friction arises in the mounting of the parts.

Although I have illustrated and described only one embodiment of myinvention, it is to be understood that it may be modified in many wayswithout departing from the spirit and scope of my invention.

I claim as my invention:

1. An equalizer for connecting a plurality of hoisting cables to a load,comprising a housing, a plurality of bars provided with adjacent beveledfaces slidably disposed in said housing, said housing and said barshaving cooperating straight sides in planes parallel with thelongitudinal axes of the bars for preventing lateral movement thereof,means for connecting the housing to the load, means for individuallyconnecting the bars to the cables, and an equalizing member mounted inthe casing in engagement with the beveled faces of the bars forcontrolling the relative longitudinal movement of the bars in accordancewith the tension of the cables.

2. An equalizer for connecting a plurality of hoisting cables to a load,comprising a housing, a plurality of bars provided with adjacent beveledfaces slidably disposed in said housing, said housing and said barshaving cooperating straight sides in planes parallel with thelongitudinal axes of the bars for preventing lateral movement thereof,means for connecting the housing to the load, means for individuallyconnecting the bars to the cables, and a roller mounted in the casing inengagement with the beveled faces of the bars for controlling therelative longitudinal movement of the bars in accordance with thetension of the cables.

3. An equalizer for connecting a plurality of hoisting cables to a load,comprising a housing, means for connecting the housing to the load, apair of bars slidably disposed in the housing and having adjacentbeveled faces, means for individually connecting the bars to the cables,a roller, means for rotatably and movably supporting the roller in thehousing in cooperative engagement with the beveled faces of the bars forpermitting relative longitudinal movement thereof in accordance with thetension on the cables.

4. An equalizer for connecting a plurality of hoisting cables to a load,comprising a housing, means for connecting the housing to the load,apair of bars slidably disposed in said housing and having adjacentbeveled faces, means for individually connecting the bars to the cables,a wheel, means for rotatably mounting the wheel in the housing, and aroller disposed in engagement with the periphery of the Wheel and theadjacent beveled faces of the bars to control the relative longitudinalmovement of the bars in accordance with the tension of the cables.

5. An equalizer for connecting a plurality of hoisting cables to a load,comprising a housing, a plurality of bars provided with adjacent beveledfaces slidably disposed in said housing, said housing and said barshaving cooperating straight sides in planes parallel with thelongitudinal axes of the bars for preventing lateral movement thereof,means for connecting the housing to the load, means for individuallyconnecting the bars to the cables, a Wheel, means for rotatablysupporting the wheel in the housing, and a roller disposed in engagementwith the periphery of the wheel and the beveled faces of the bars forcontrolling the relative longitudinal movement of the bars in accordancewith the tension of the cables.

6. An equalizer for connecting a plurality of hoisting cables to a load,comprising a housing, a pair of bars having adjacent beveled facesslidably disposed in said housing, the cooperating sides of said housingand said bars being constructed to prevent lateral movement and morethan a predetermined longitudinal movement of said bars, means forconnecting said bars to a plurality of hoisting cables, a wheel, a shaftfor rotatably mounting said wheel in said casing, an equalizing roller,and means for rotatably and movably supporting said roller from saidshaft with the periphery of the roller in cooperative engagement withthe periphery of the wheel and the adjacent beveled faces of the bars.

7. An equalizer for connecting a plurality of hoisting cables to a load,comprising a housing, a plurality of bars provided with adjacent beveledfaces slidably disposed in said housing, said housing and said barshaving cooperating straight sides in planes parallel with thelongitudinal axes of the bars for preventing lateral movement thereof,antifriction elements disposed between the cooperating straight sides ofthe bars and the housing, means for connecting the housing to the load,means for individually connecting the bars to the cables, and anequalizing member mounted in the casing in engagement with the beveledfaces of the bars for controlling the relative longitudinal movement ofthe bars in accordance with the tension of the cables.

8. An equalizer for connecting a plurality of hoisting cables to a load,comprising a housing, a plurality of bars provided with adjacent beveledfaces slidably disposed in said housing, said housing and said barshaving cooperating straight sides in planes parallel with thelongitudinal axes of the bars for preventing lateral movement thereof, aplurality of rollers disposed between the cooperating straight sides ofthe bars and the housing, cages for the rollers, means providing lostmotion connections of the cages with the bars to maintain the rollers inoperative position, means for connecting the housing to the load, meansfor individually connecting the bars to the cables, and an equalizingmember mounted in the casing in engagement with the beveled faces of thebars for controlling the relative longitudinal movement of the bars inaccordance with the tension of the cables.

'9. An equalizer for connecting a plurality of hoisting cables to aload, comprising a housing, a plurality of bars provided with adjacentbeveled faces slidably disposed in said housing, said housing and saidbars having cooperating straight sides in planes parallel with thelongitudinal axes of the bars for preventing lateral movement thereof,means for connecting the bars to the cables, and an equalizing membermounted in the casing in engagement with the beveled faces of the barsfor controlling the relative longitudinal movement of the bars inaccordance with the tension of the cables, and removable means forholding the bars in fixed relation to each other and to the housingafter they are assembled until the equalizer is placed in operation.

JAMES DUNLOP.

